Finding Nemo 9: Revolution Underwater

Finding Nemo 9

Revolution Underwater

To explore deep sea habitats and biodiversity in the Tasman Sea, a joint Australian-New Zealand research voyage carried leading Australian, New Zealand and other international scientists to uncover new marine species and habitats. The NORFANZ research voyage explored deep sea habitats around seamounts and abyssal plains around Lord Howe and Norfolk Islands through to northern New Zealand. The voyage collected biodiversity samples, DNA tissue samples, seabed habitat data, photographs and video on seamounts at depths between 200 meters and 1.2 kilometers, and surveyed free-swimming animals that live in the water masses above and around these seamounts. Australia’s National Oceans Office – the body responsible for developing and implementing Australia’s Oceans Policy – and the New Zealand Ministry of Fisheries supported the four-week voyage between 10 May and 8 June.

With cooperation from the National Oceans Office , the NASA-sponsored Astrobiology Magazine chronicles the scientific notes written by the researchers onboard. As the director of the Hayden Planetarium, Neil Tyson, wrote about the marvels of biodiversity: "I do not know whether biologists walk around every day awestruck by the diversity of life. I certainly do. On this single planet called Earth, there co-exist (among countless other life forms), algae, beetles, sponges, jellyfish, snakes, condors, and giant sequoias. Imagine these seven living organisms lined up next to each other in size-place. If you didn’t know better, you would be hard-pressed to believe that they all came from the same universe, much less the same planet".

The main goal of the summer expedition mirrored that sentiment: to provide baseline information on the, nature and potential vulnerability of these unique habitats and their biodiversity. The results will give scientists interested in biodiversity a much better understanding of the species that live on and around the deep seamounts and ridges throughout the Tasman Sea, many of which were new to science. The information will also enhance and contribute to international collaboration in oceans management.

Big afternoon and evening yesterday. Returning to the area of the million brittle stars, a Sherman sled, an orange roughy trawl and a beam trawl were sent down at different depths. The sled was on the slope, at around 700 metres (170 m deeper than yesterday’s live brittle star aggregations). It seemed to be where all the shells and other hard remains slid down to when they die. There were very few live animals in the shell gravel collected in this trawl. The next two nets were shallower and brought up more interesting creatures, again mainly invertebrates. It took the night invertebrate crew another six hours to sort this catch, identifying more than 80 species. One of the weirdest was a large sponge that looked like a cross between a bush and a large whale bone. Crabs, shrimps and serpent stars were living in its nooks and crannies.

Fish catches have also been interesting, including a long-finned gemfish (Rexea antefurcata), a prickly shark, a leopard chimaera (Chimaera panthera), red dory (Cyttopsis roseus), mirror dory (Zenopsis nebulosus) and New Zealand frostfish (Lepidopus caudatus). The stomach of one frostfish contained a small deep-sea cardinalfish that was named after Lord Howe Island (Howella sherboni). This catch also included a few Richardson’s Boarfish (Pseudopentaceros richardsoni), a species that has been found to congregate around seamounts in large numbers and has been heavily fished in the past.

Becoming a regular theme on this trip, yesterday saw a dramatic increase in the world’s collections of another rarely caught fish. The small rattail fish, Caelorinchus cylindricus , was recently described from New Caledonia by Tomio Iwamoto (who is on board) on the basis of a single animal. In one day of sampling, the world tally has now risen to nine specimens. These extra specimens will be distributed amongst the reference collections of the organizations represented on board.

What happens to all these collected invertebrates and fishes? Are they of any value? Or do they just get rammed in some basement and forgotten? The answer to the last question is a definite "no". These specimens are of enormous value. All are preserved and transported to government museums and reference collections where all are identified, catalogued, assigned registration numbers and stored in accessible climate-controlled research collections. Where necessary, specimens are loaned to experts around the world to get material identified. Museum and research collections house, curate and do active research on these valuable voucher specimens.

These reference collections play many important roles, most of which are not seen by the general public. These include being:

A repository for the actual specimens to which new names are formally attached (known as type specimens").
* A reference collection for studies on biodiversity, conservation, human impacts, ecology and evolution.
* An aid to species identification s for customs, quarantine, fisheries, the seafood industry, pest control and studies of introduced species.
* Specimens and information for public education programs, publications, exhibitions and displays.
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These collections also provide a snapshot in time. If things like climate change have a major impact on life in our seas, it will be data from museum collections that will allow it to be detected. The aim of these collections is to keep these specimens and all their associated information, images and tissue samples in good accessible condition, for ever. Because of museum collections, many of the animals on which Darwin based his theory of evolution are still intact today. So are other specimens dating back to the middle ages. Museums house the only remains of the Tasmanian Tiger, the Dodo, the Flightless Auk and the Stellar Sea Cow, as well as many other recently extinct animals.

So a dead fish is not just a dead fish. It provides information on many things. All this information is critical for sound management of natural systems.

Back to the voyage. There was another long steam overnight and now the sound velocity probe has just gone down in 1200 m of water to allow the seabed mappers to calibrate the multibeam scanner. Then we can choose appropriate ground to sample.

The choice of sites is a collaborative effort between the voyage leader, scientific staff, shift leaders, multibeam mappers and the captain or mate. Scan maps are generated, rock hardness is assessed and flat ground is sought. Sample sites are chosen at a range of set depth levels and appropriate sampling gear is selected. The deck crew deploy the nets on the say of the captain or mate, and transponders on the net and doors show the exact position of the net underwater so that it can be set down accurately on the best ground.

The sun is getting low in the west in the late afternoon and the weather has continued to be kind to us. Yesterday afternoon was again busy. First the orange roughy net came up with some interesting animals, some of which were a bit worse for wear because of a less welcome passenger, a seal shark (see creature feature"). This shark is one of the cookie cutter sharks that manages to take perfect round holes out of anything within biting range. As a consequence, many of the animals in the catch had big chunks bitten out of them. This catch also included a different stone crab species, some great condition jewel squids and a new skate species, which is deep blue in colour.

The beam trawl went out next and came back absolutely packed with dead shells and coral rubble. The pile spread over the back deck and became a team effort to heave more than 20 fish bins full to the invertebrate sorting area. The night shift then spent four hours sifting through this pile, mainly extracting small crabs, shrimps, sea urchins, brittle stars and several large sea spiders.

The next beam trawl came up with several un-collapsed collapsible sea urchins (Phormosoma sp) complete with poisonous spines, so they had to be handled carefully.

This morning’s ratcatcher at 4 am sampled down to 1.2 km deep and contained a rich mix of species including slickheads, rattails, small sharks, tripodfish, basketwork eels, snipe eels, another blobfish, viperfish, hatchetfish, orange roughy and a large chimaera. It also included a tiny long-nosed chimaera and two more of the new blue skates.

In many of our trawls we have been getting what look like big blobs of snot. They are generally torn up, but when you float out the intact ones in water you find that they are egg-shaped animals with an obvious gut and a star-shaped structure at one end. These are actually jelly-like sea cucumbers that swim (rather than crawl along the seafloor as their more muscular relatives do). The jelly-like flesh helps make the animal buoyant so that it can float along and descend to the seafloor to lick up any organic matter ("detritus") that has settled on the mud. This buoyancy saves energy compared with living on the seafloor and trying to wade through fine soft mud. Saving energy is a common theme in the deep sea as food is scarce, so animals need to travel very efficiently. Many animals use jelly-like flesh to make themselves float or hang mid-water. Most of this jelly is made up of compounds called glycosaminoglycans" that have a very low density. These compounds cancel out the weight of any muscles or hard structures. Some sluggish deep-sea fishes and squids use this jelly system of buoyancy.

Bruce Barker from CSIRO has been deploying the drop camera for the last couple of days, after he and the crew modified it to fit the Photo Sea camera system. He has developed the films and produced some dramatic images of the different habitat types that we have been sampling in this region. One on rocky ground shows a large fan coral (gorgonian) with other sessile animals (anemones and corals) attached. Another rocky ground shot has small fan corals and a fan sponge as well as a scorpionfish waiting for a feed. The camera also photographed the million brittle star" site and showed why we caught so many. One photo of the muddy seafloor shows brittle stars spread evenly over the entire surface.

Until now there has been no mention of the most important people on this ship. Without their efforts, there would not be a single trawl, no specimens would be caught, identified, photographed or preserved. These people are the cooks, Kim Ashby and Yvonne French, and steward Dave Chapman who have been keeping us all very well fed and happy. The food has been excellent, possibly too excellent, as some on board head back for third helpings of dessert. Many thanks to these three people for all their efforts.

Another day, another skate. Last night brought in yet another new skate species, this time one with spines all over the underside, suggested as an adaptation for living on rough rocky ground. It is species F" in a new genus of skates. Last night also saw a catch of large mature Richardson ‘s boarfish off the top of a seamount. Seamounts often act as sites for large breeding aggregations of deep-water fishes. This has lead to very heavy commercial fishing of such aggregations and subsequent declines in species such as orange roughy. Last night also saw the first New Zealand record for a whole family of fishes (family Draconettidae) from one small fish in the genus Centrodraco.

The real revolution of this special collaborative voyage has been the rapid onboard generation of the detailed and extensive photo reference folders. These allow immediate recognition of species (named or new) that have already been encountered in the course of the voyage. Producing these folders has been a massive task. All the digital fish photographs have been taken by Robin McPhee of Te Papa and Australian Museum staff, Mark McGrouther (first leg) and Kerryn Parkinson (second leg). Photos go into a temporary folder for review by fish experts onboard and are then coded and placed in the final reference folders. So far four large fish volumes of detailed fish identification sheets have been produced for more than 500 fish species.

For the invertebrates, the even larger task (because of the higher diversity) has primarily been taken on by Karen Gowlett-Holmes of CSIRO, who has done an enormous amount of work to produce and keep up to date the invertebrate folders. She has been aided with the photography in the day shifts by Phil Alderslade (first leg) and me (second leg). At this stage of the trip, more than 1300 species worth of invertebrate identification sheets have been produced. Keeping these folders up to date can be a nightmare. Last night’s beam trawl brought in 114 species of invertebrates of which many are new additions. In one Sherman sled a few days ago there were 60 new species additions in a single catch. This means to keep the folders current, Karen has to edit up to 100 images (as some species need both wide and close-up shots), assign code numbers and print all the images. This is just for one sampling station.

Each different species recognised on this trip has been assigned a CAAB code (Codes for Australian Aquatic Biota). This code places animals in their family groups and assigns a unique number for each as a way of dealing with changing taxonomy (such as reviews of groups that change scientific names) or the delays and slow process of getting new species described. These codes are linked with collection information, images, specimens and tissue samples.

All the information generated on this trip is entered on to the onboard database. After a sample, the details of the sampling station are entered directly from the bridge. Catches are identified and data sheets are filled in by each group. These then go to Brent Wood and Neil Bagley who enter everything on the ship’s network, assisted by Malcolm Clark, Peter McMillan and Kevin Mackay. Data verification is critical as errors significantly weaken the value of this information. Any anomalies found on data sheets are checked back with the sources. The final print out is then compared to the original catch notes. The resulting data set allows immediate analysis and the capacity to generate all sorts of summaries, e.g., by species, by station, by depth, by gear, by location or by seamount. Maps such as the one shown can be generated by scientists on board for their particular groups, summarizing the locations and scale of catches for each station of the NORFANZ cruise. These maps are generated using public shareware from Generic Mapping Tools and Smith and Sandwell (satellite-derived seafloor bathymetry). The system is very efficient and at the end of NORFANZ, all participants are handed a CD with the full data set for the voyage.

The beam trawl came up at lunch time from 850 metres with sea urchins, sea stars, hundreds of miniscule white scallops, ribaldos, several coffinfish species and some rattails. A ratcatcher to around 800 m has just come up with a load of fish and nine spectacular small shrimp (see creature feature"). More tomorrow for our last day of bottom trawling.

The Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the New Zealand National Institute of Water and Atmospheric Research Ltd (NIWA) are providing scientific support for the voyage. The NORFANZ voyage will use NIWA deep-sea research vessel, the R.V. Tangaroa (NORFANZ).

The expedition received considerable interest from scientists worldwide. Twenty four scientists from more than eleven research organisations will be represented onboard, including staff of CSIRO, Hobart; Museum Victoria; the University of Tasmania; Australian Museum; Queensland Museum; Northern Territory Museum; NSW State Fisheries; Te Papa, Wellington; National Institute of Water and Atmospheric Research, New Zealand; Institute de Recherche pour le Développement, Noumea; Natural History Museum, Paris; and California Academy of Sciences, San Francisco.